Reciprocating Compressor

Reciprocating Compressor

Similar to an automotive combustion engine, except passive non return valves replace actuated valves.

A piston travels up and down inside a cylinder, and is connected to a crank shaft by a connecting rod.

On the intake stroke, the discharge valves are forced shut, and gas is therefore sucked into the cylinder.

On the compression stroke the suction valves are forced shut, and gas is expelled into the discharge port.

On multi-stage machines, the gas must be cooled before entering the next stage.

Typical Performance Envelope
 
  Imperial Metric
 
Minimum swept volume 10 cfm 17 m3/h
 
Maximum swept flow 15,000 cfm 25,000 m3/h
 
Maximum casing pressure 5,800 psi 400 bar
 
Maximum pressure ratio per stage 3.5  
Advantages
 
  • High efficiency.
  • Very high pressures possible, with multiple stages.
  • Resistant to corrosive gases and particulate.
Disadvantages
 
  • Regular maintainance requirement.
  • Fixed speed – not easy to control flow.
  • Out of balance forces mean a special foundation is required.
  • Noisy.
  • Pulsating gas at discharge may need damping.
  • Complicated – many moving parts.
  • Efficiency drops off between overhauls.
Common Applications